Reversible regenerative furnace



April 14, 1936. o. REINER REVERSIBLE REGENERATIVE FURNACE Filed Nov. 21, 1934 3 Sheets-Sheet 1 meys April 14, 1936. Q EINE 2,037,149

REVERSIBLE REGENERATIVE FURNACE Filed Nov. 21, 1934 3 Sheets-Sheet 2 lnvenfor: 6- Rel '16 2 y I; /gornevs April 14, 1936.

0. REINER REVERSIBLE REGENERATIVE FURNACE Filed NOV. 21, 1934 3 Sheets-Sheet 3 Fuji W W W Patented Apr. 14, 1936 PATENT OFFICE 2,037,149 RE JER SIBLE REGENERATIVE FURNACE Otto Reiner, Rheinhausen/Niederrheln, Germany Application November 21, 1934, Serial No. 754,132 In Germany November 25,1933

' 15 Claims. (01.203-52) operation, or change of period, as a portion of the a heating gas goes to waste through the chimney flue. It has been proposed to provide, in the main gas pipe, a valve, a slide, a damper, or the like, and to cut off the supply of gas by such means when, or before, the reversing means is operated.

This mode of operation, however, is only feasible if the furnace is heated by one gas only, and not with a mixture of not less than two gases. If, on the other hand,the furnace is heated by such mixture, say, by a mixtureof one valuable gas, such as coke gas, and blast furnace gas, or by a mixture of two valuable gases, such as coke gas and producergas, and blast furnace gas, the aforesaid means for cutting off the supply of mixture in the main gas pipe would involve considerable difliculties. The principal cause of, this trouble is that the individual gases are under different pressures in the pipes conducting them to the main pipe where they are mixed, and that the point where such mixing occurs, is at a short distance from the gas reversing valve, or even in this valve.

Now if the main gas pipe is shut down, the pro-' portion of the various gases in the mixture will be determined by their individual pressures, and

the percentage of a given gas in the mixture would be the greater, the higher its pressure. Such a mixture in which the percentage of the individual gases is a function of their relative pressures, is obviously not the proper mixture by which the furnace is intended to be operated. The proper mixture has a definite heating value to which the supply of air is proportioned, and if this proportion ceases to exist, in particular, if

the mixture is too rich, the supply of air. is inade-' quate for combustion, and a portion of the mixture, or even its major portion, is not fired and goes to waste.

/ Providing a shut-down valve in the main gas pipe has the additional drawback that, when the gas supply has been cut off by such valve, the valuable gas mixture which is still present in the chambers and passages of the furnace, goes to waste as often as the gas-reversing valve is operated, and this loss may be of the order of 4000 cubic feet.

With the object of my invention in mind, i. e., with the object of eliminating the said reversing loss, I operate the furnace as follows: 5

. Before the furnace is reversed, I cut off the supply of the valuable .gas, or gases, but not the supply of the less valuable gas, so that the less valuable gas expels the mixture still present in the furnace, to the burner. When this residual mixture has been consumed, the furnace is reversed and the supply of the less valuable gas is also cut off.

Preferably, the valves by which the flows of the individual gases are controlled, are reopened at the same time after the furnace has been reversed.

It is preferred, particularly in the operation of comparatively large regenerative furnaces, to throttle the supply of the less valuable gas durin the operating periods of the furnace, to open it 20 fully when the supply of the valuable gas, or gases, is cut off, and to cut off the supply of less valuable gas when the furnace is reversed. By first throttling, and then fully opening, the supply of the less valuable gas, the amount of such gas admitted to the furnace per unit of time is increased during the period for which the supply of more valuable gas has been cut off, i. e., while only less valuable gas is admitted. Supplying more less valuable gas per unit of time during the said period than while the furnace is in normal operation, is preferable as it makes up for the missing volume of valuable gas. v

In the accompanying drawings, a regenerative 5 furnace without, and one with, the aforesaid 'means for throttling the supply of less valuable gas during the normal operation of the furnace, are illustrated by way of example.

In the drawings: 40

Fig. 1 is a sectional elevation of the first-mentioned furnace,

Fig. 2 is a similar elevation of the other furnace, and

Figs. 3 to 5 are elevations, drawn upon a larger scale, showing three positions of the valves by which the flow of the less valuable gas is controlled. j

Referring now to the drawings, and first to Figs. 1 and 2, gas mixture is supplied to a central chamber C of the furnace through an inlet port l5 which is connected to a mixing chamber l5, and the mixture is distributed by a rotary gasreversing valve I. Air is supplied through an air pipe A,, and distributed. by an air-reversing valve 2. Both reversing. valves are of the twoway type, with a central partition I' and 2', respectively.

The casing of the gas-reversing valve I is connected to two gas-regenerator chambers 4 and I8, at opposite sides of chamber C, by pa s-' and to the burner 5 by passages 'I" and I1",

respectively. All four chambers are equipped with the usual checkerwork bricks. A chimney flue II connects the casings of valves I and 2.

In the position of the reversing valves I and 2 which is illustrated in full lines, mixture from the mixing chamber I5 flows to burner 5 through I5, valve I, passage 3, gas-regenerator chamber 4, with its checkerwork, and passage 4". Air flows to the burner 5 from valve 2 through 6, I, and 'I". The mixture entering at the right in the direction of the arrow, expels the" waste gases at the left. The waste gases flow to the chimney flue II through I6", I6, I6, and gas-reversing valve I, and through l1", l1, l1, and air-reversing valve I.

' When the furnace is reversed by moving the valves I and 2 into the dotted-lines position, the flows ,ofmixture and air are also reversed, gas and air now flowing to the burner 5 through chambers I6 and I1, respectively, and the waste gases flowing to the chimney flue II through chambers 4 and I.

Referring now particularly to Fig. 1, three as pipes 8, 9, and Ill open into the mixing chamber I5. The pipes 8 and 9 each supply a valuable gas for instance, coke gas in the pipe 8, and producer gas in the pipe 9, and a less valuable gas, such as blast furnace gas, flows in pipe I0. Obviously, I am not limited to the example illustrated, as only one of the pipes 8 or 9, or more than two pipes for supplying valuable gases, might be provided. Similarly, more than one pipe III for supplying less valuable gases might be provided.

Each gas supply pipe 8, 9, and I9 is equipped with a valve and the valves are shown as butterfly valves I2, I3, and I4, respectively. The valves I2 and I3 in the respective pipes 8 and,9 for the valuable gases are operated by a shaft 4| to which movement is imparted by a gearing 40 from a motor M. Gearing 42, 43, and 44 connects the shaft H to the thirdvalve, I4, in the pipe II) for the less valuable gas. The mechanism for controlling the valves is so designed that the valves I2 and I3, for the valuable gases, are closed a short time before the furnace is reversed by valves I and 2 while the valve I4, for the blast furnace gas, remains open for the present. By these means, only blast furnace gas is admitted to the furnace after valves I2 and I3 have been closed. and expels the residual mixture in the furnace through gas-reversing valve I, passage 3, and chamber 4 into the burner 5 where it is consumed. Thereupon, the air-and-gas-reversing valves 2 and I are reversed by moving them into the dotted line position, and, at the same time, the valve I4 in the pipe III for the blast furnace gas is closed. At thetime the valves I and 2 are reversed, only the less valuable furnace gas is present in the furnace and goes to waste through the chimney flue II but there is no loss of valuable gas. When the valves I and 2 have been reversed, and the furnace is ready for the next cycle, the valves I2, I3 and I4 in the respective gas pipes 8, 9, and III are opened at the same time.

Any other means than the motor M may be provided, and it is not necessary that this should be an electric motor. The valve I4 in the pipe III for the less valuable gas might also be equipped with an (electric or other) motor of its own. Under all conditions, the valve I4 must lag with respect to the other two valves. This is easy if I the valve I4 has a motor of its own but may also be effected in various ways if there is only one motor M for all three valves, as illustrated. Thus, a clockwork might be wound by the closing movement of valves I2 and I3 and, after a certain time, close the valve I4. Obviously. the mechanism for operating the valve I4 must be so designed that the valves I2 and I3, when being opened, open the valve I4 at the same time, for which purpose a suitable gearing or system of links and levers may be directly connected to the means for controlling the valves I2 and I3.

The several variations referred to have not been illustrated as the mechanisms which may be used for them, are old in the art and easily understood without illustration.

Referring now to Figs. 2 to 5, the valves I2 and I3 in the respective pipes 8 and 9 are provided as described and operated by a motor M as shown 'in Fig. 1, or by any other suitable means not shown. The valve I4 is replaced by a pair of valves 20 and 2I, both shown as butterfly valves, in a valve casing I II which is inserted between the pipe I and the mixing chamber I5. The valve 20 is mounted on a. shaft 22, and the valve 2| is mounted on a shaft 23, in the valve casing I0. Secured on the shaft 22 of valve '29 outside the casing I0 is an arm 24 on which is mounted a weight 25. An arm 26, with a crank pin 21, is mounted to turn freely on the shaft 22 and is operated by an electric or other motor, not shown. A dog 29 is keyed on the shaft 22 and its oscillating movement with the shaft is limited by an upper check 30, and a lower check 35. Both checks are adjustable. Another arm 3| is also keyed on the shaft 22 and equipped with a block 32 at .its free end, for engaging the arm 26.

The crank pin 21 at the free end of the arm 26 is adapted to engage in a fork 28 on the shaft 23 of valve 2|. The fork 28 oscillates between two checks 33 and 36. I

-Fig. 3 shows the position of the valves during the normal operation of the furnace. The valve 2I is full open, and its fork 28 engages the lower check 33. The .dog 29 on the shaft 22 of valve 20 engages an inclined face at the right of check 30, and the block 32 at the free end of arm 3I bears against the arm 26 from the right. The valve 20 is inclined at an angle of about 45 degs. for throttling the flow of the blast furnace or other less valuable gas from pipe III.

When it is desired to reverse the valves I and 2 of the furnace, the two valves I2 and I3 are closed a short time before the valves I and 2 are valve 20 does not open fully when the dog 29 is on the check. The blastfurnace gas now expels the residual mixture in the furnace and causes it to be consumed, as described. The valves I and 2 are now reversed and, at the same time the arm 26 is turned further in the direction of arrow 34, until it is arrested by an inclined face at the left of check 30. This movement of the arm 26 causes the forli 28 to move as far as the check 36, and the valve 2| is closed, as shown in Fig. 5. The-supply of blast furnacegas to the mixing chamber I5 is now out off.

When thevalves l and 2 have been reversed, the valves. l2 and I3 in the pipes 8 and 9 are opened, and-at the same time thearm 26 is returned into theposition i lustrated in Fig. 3 against the arrow 34. The return of the valves may beeffected by any suitable means. If the arm 26 is made heavy enough, it will return into its initial position, Fig. 3, under the action of its own wefght but obviously it might be equipped with a weight or spring (not shown) for returning it. The fork 28 is released and returns to the lower check 33, also by gravity, moving the valve 2| into its open or horizontal position. Immediately after, the arm 26, through block 32 and arm 3|, moves the valve 20 into its throttling position, so that the parts are now again in the position illustrated in Fig. '3, and the furnace is ready for the next operation. Obviously, other means than electric motors and a time switch might be used for operating the valves.

I claim:

1. In a regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a m xing chamber, a gas-reversingvalve for alternately connecting said mixing chamber to said gas regenerators, means for supplying air to said air regenerators, an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, pipes for supplying various gases to said mixing chamber, and means for controlling the flow of the gas in each pipe.

2. In a regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternately connecting said mixing chamber to said gas regenerators, means for supplying air to said air regenerators, an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, pipes for supplying various gases to said mixing chamber, and means for controlling the flow of the gas in each pipe in time with the operation of said reversing valves.

3. In a regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternately connecting said mixing chamber to said gas regenerators, means for supplying air to'said air regenerators, an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, pipes for supplying various gases to said mixing chamber, means for controlling the flow of the gas in each pipe, means for operating one of said controlling means to cut off the supply, and means lagging with respect to said first-mentioned means, for operating the other controlling means to cut off the supply.

4. In a regenerative furnace, a burner, gas rcgenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternateiy connecting said mixing chamber to said gas regenerators, means for supplying air to said regenerators, an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, pipes for supplying various gases to said mixing chamber, means for controlling the flow of the gas in each pipe, meansfor operating one of said controlling means to cut off the supply, and means lagging with respect said first-mentioned means, for operating the other controlling means to cut off the supp'y, and means for causing both controlling means to reestablish the supply at the same time.

. 5. Ina regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternately connecting said mixing chamber to said gas regenerators, means for supplying air to said air regenerators, an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, a pipe for supplying a valuable gas to'said mixing chamber, another pipe for supplying a less valuable gas to said mixing chamber, means for controlling the flow of thegas in each pipe, means for operating the controlling means of the valuablegas pipe to cut off the supply of valuable gas, and means lagging with respect to said operating means for operating the controlling means of the other pipe to cutoff the supply of less valuable as. v

6. In a regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternately connecting said mixing chamber to said gas regenerators, means for supplying air to said air regenerators, an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, a pipe for supplying a valuable gas to said mixing chamber, another pipe for supplying'a less valuable gas to said mixing chamber, means for controlling the flow of the gasin each pipe, means for operating the controlling means of the valuable-gas pipe to out off the supply of .valuable gas, means lagging with respect to said operating means for operating the controlling means of the other pipe to cut off the supply of less valuable gas, and means for causingboth controlling means to re-establish the supply at the same time.

7. In a regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternately connecting said mixing chamber to said gas regenerators, means for supplying air to said air regenerators, an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, a pipe for supplying a valuable gas to said mixing chamber, another pipe for supplying a less valuable gas to said mixing chamber, means for controlling the flow of the gas in each pipe, means for operating the controlling means of the valuable-gas pipe to cut off the supply of valuable gas, means lagging with respect to said operating means for operating the controlling means of the other pipe to cut off the supply of less valuable gas, and means for throttling the supply of the less valuable gas while the supply of the valuable gas is on, and for laying the supply of the less valuable gas fully open when the valuable gas is off.

8. In a regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternately connecting said mixing chamber to said gas regenerators, means for supplying air to said air regenerators, an air-reversing valve for alternately connecting said air regenerat rs to said air-supplying means, a pipe for supplying a valuable gas to said mixing chamber, another pipe for supplying a less valuable gas to said mixing chamber, a valve in each pipe, means for opening and closing the valve in the valuable-gas pipe, and means for controlling the valve in the pipe for, the less valuable gas so as to throttle the flow of the less valuable gas while the valve in the valuable-gas pipe is open, and to fully open the flow of the less valuable gas when the valve .in the valuable-gas pipe has been closed.

9. In a regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternately connecting said mixing chamber to said gas regenerators, means for supplying air to said air regenerators,. an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, a pipe for supplying a valuable gas to said mixing chamber, another pipe for supplying a less valuable gas to said mixing chamber, a valve in said valuable-gas pipe,

means for, opening and closing said valve, a

throttling valve and a closing valve arranged one behind the other in the pipe for the less valuable gas, and means for holding said throttling valve in throttling position with respect to the flow of less valuable gas, for holding the closing valve in fully open position with respect to such flow while the valve in the valuable-gas pipe is open, for moving said throttling valve into fully open position when the valve in the valuable-gas pipe is closed, for moving said closing valve into closing position without moving said throttling valve from its fully open position, and for first returning the throttling valve into throttling position, and then returning the closing valve into fully open position, after the valve in the valuable-gas pipe has been re-opened.

10. In a regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternately connecting said mixing chamber to said gas regenerators, means for supply n air to said air regenerators, an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, a pipe for supplying a valuable gas to said mixing chamber, another pipe for supplying a less valuable gas to said mixing chamber, a valve in said valuable-gas pipe, means for opening and closing said valve, a throttling valve and a closing valve arranged one behind the other in the pipe for the less valuable gas, a shaft for each valve mounted to turn in the pipe for the less valuable gas, an arm mounted to turn freely on the shaft of said throttling valve, means tending to move said throttling valve into fully open position, one-way means operatively connected to said. arm for holding said throttling valve in throttling position in one position of said arm, and for allowing it to move into fully open position when the arm is moved from said position, and means on the shaft of said closing valve tending to move said closing valve into fully open position and adapted to be engaged by said arm to close said closing valve independently of said throttling valve.

11. In a regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternately connecting said mixing chamber to said gas regenerators, means for sup:- plying air to said air regenerators, an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, a pipe for supplying a valuable gas to said mixing chamber, another pipe for supplying a less valuable gas to said mixing chamber, a valve in said valuable-gas pipe, means for opening and closing said valve, a throttling valve and a closing valve arranged one behind the other in the pipe for the less valuable gas, a shaft for each valve arranged to turn in the pipe for the less valuable gas, a weight connected to the shaft of said throttling valve for turning said shaft and moving said throttling valve into fully open position, an arm mounted to turn freely on the shaft of said throttling valve, a block operatively connected to the shaft of said throttling valve and adapted to bear against said arm on one side under the action of said weight, a fork on the shaft of said closing valve for moving said closing valve into fully open position by gravity, and means on said arm for engaging said fork to move said closing valve into closing position independently of said throttling valve.

12. In a regenerative furnace, a burner, gas regenerators and air regenerators connected to said burner, a mixing chamber, a gas-reversing valve for alternately connecting said mixing chamber to said gas regenerators, means for supplying air to said air regenerators, an air-reversing valve for alternately connecting said air regenerators to said air-supplying means, a pipe for supplying a valuable gas to said mixing chamber, another pipe for supplying a less valuable gas to said mixing chamber, a valve in said valuable-gas pipe, means for opening and closing said valve, a throttling valve and a closing valve arranged one behind the other in the pipe for the less valuable gas, a shaft for each valve mounted to turn in the pipe for the less valuable gas, a weight connected to the shaft of said throttling valve for turning said shaft and moving said throttling valve into fully open position from throttling position, a pair of) adjustable checks for holding said throttling valve in its two positions, an arm mounted to turn freely on the shaft of said throttling valve, a

block operatively connected to the shaft of said throttling valve and adapted to bear against said arm on one side under the action of said weight for holding said throttling valve in throtthng position, a fork on the shaft of said closing valve for moving said closing valve into and gas mixture, reversing the flows, and cutting oil the supply of less valuable gas.

14. The method of operating regenerative furnaces, comprising supplying to the burner of the furnace air, not less than one valuable heating,

gas, and not less than one less valuable gas, mixing said gases before admitting them to the gasregenerator of the furnace, cutting off the supply of valuable gas before reversing the flows of'air and gas mixture; reversing the flows, and, at the same time, cutting oif the supply of less valuable gas.

15. The method of operating regenerative furnaces, comprising supplying to the burner of the furnace air, not less than one valuable heating gas, and not less than one less valuable gas,

. mixing said gases before admitting them to the the previously throttled less valuable gas after the supply of valuable gas has been cut oil; reversing the flows or air and gas mixture, and cutting ofl'the supply of less valuable gas.

O'I'I'O REIN'ER. 

